Drain-valve for air-brake systems and the like.



. T. W. DEMAREST.

DRAIN VALVE FOB AIR BRAKE SYSTEMS AND THE LIKE.

v APPLICATION FILED AUG.I4. I916. 1 ,278, 1 1 8. Patenwd Sept. 10, 1918.

. IVA w UNITED. STATES PATENT OFFICE.

THOMAS W. DEMAREST, FORT WAYNE, INDIANA, ASSIGNOR TO OKADEE COMPANY,

' OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

DRAIN-VALVE FOR AIR-BRAKE SYSTEMS AND THE LIKE.

Specification of Letters Patent.

Patented Sept. 10, 1918.

Application filed August 14, 1916. Serial No. 114,892.

To all whom it may concern: I

Be it known that I, THOMAS W. DEMAREST, a citizen of the United States, and a resident of Fort Wayne, in the county of Allen and State of Indiana, have invented certain new and useful Improvements in Drain-Valves for Air Brake Systems and the like, of which the following is a specification.

My present invention relates in general to draining devices and more particularly to means for draining systems and apparatus employing compressed fluids wherein water of condensation has a tendency to collect,

and has special reference to the provision of improved automatically active means for draining air brake systems.

In the air brake systems as arranged at the present day wherein the air for the operation of the system is stored in a main reservoir, unless extraordinary care is used to prevent it, there is a tendency toward the undue accumulation of water of condensation in such main reservoir, which is objectionable for reasons among which are the following: cuttin down of capacity of the main reservoir; orcing the water into the system which in cold weather has a tendency to collect in thevalves and traps and form ice, thereby retarding the operation of certain parts of the apparatus even to the extent of rendering it unoperative, or at best rendering the system, as a whole, sluggish in operat1on.

This water of condensation arises from the known phenomenon of the precipitation of water when compressed air expands, and to overcome the objections ensuant upon such precipitation, it is the practice to drain the main reservoir manually at frequent intervals. Inasmuch, however, 'asthis procedure depends upon the memory of round-.

house .attendants, absolute reliance cannot be placed "upon such a method of draining. The objects of my present invention therefore are: the provision in asystem employing fluid under pressure, wherein water of condensation occursor where for any reason it 1s deslred to dram the Water of condensation from the system or any partthereof when. the pressure in one predetermined part of the system is reduced or in another predetermined part of the system,

increased, of means for draining the system which is automatic in its operation; the provision of an improved automatic drain valve device for the purpose specified; the provision of an improved drain valve device characterized by the employment of a pluralit of direct connected pistons; the provision 0 an automatically active drain valve for the purpose specified, characterized by the employment of means whereby it may be manually operated; the provision of an inexpensive and efiicient drain valve device which may be readily installed and which in service will be reliable and accurate in operation and easily maintained, together with such other objects as may hereinafter appear.

In carrying out my present invention I provide a structure and an arrangement thereof in an air brake system, a preferred embodiment whereof being shown in the accompanying drawing, wherein Figure 1 is a schematic view illustrative of the application of my present improvements to a Westinghouse typeof air brake system:

Fig. 2 is a central vertical sectional view ofan improved drain valve such as is conveniently employed by vme in the system shown in Fig. 1.

Referring now more particularly to Fig. 1 of the drawings, itwill be observed thatI have here indicated (somewhat diagrammati cally) a form of locomotive air-brake equipment wherein there is employed an air-compressor A discharging airtaken in through an air inlet B, through an air-discharge pipe voir D communicates by means of a pipe E with the engineers brake-valve F, which in turn communicates by a pipe G with the brake pipe H, a stop-cock J, and an ex haust K to the atmosphere, being arranged .in, said pipe G. The brake-valve reservoir is indicated at L,- and at M the pipe leading from the brake-valve F to the governor'M which controls the admission of steam from the steam-line N into the compressor-pump. which is arranged within the casing 0. At

P is indicated an ordinary form of water- G into a main reservoir D. The mam reserto the atmosphere (not shown). The triplevalve in turn is in communication with an auxiliary-reservoir S and by a suitable connection T with a brake-cylinder V. In draining the main reservoir of the system thus described (or the battery of communicating main-reservoirs, where such is employed) 1 provide an automatic drain valve indicated at X, one side of which is in communication by pipe Y with the main reservoir D, and the other is in communication by a pipe Z with some convenient part of the system such as the pipe T above referred to.

As the general arrangement of air-brake system above outlined (with the exception of my present improvements) is well known to those skilled in the art, the component parts are not illustrated and described in detail.

Referring now more particularly to Fig. 2, wherein 1 illustrate the details of the construction of the drain-valve, X, it will be observed that the casing 10 of the valve X is provided with a pair of nipples 11 and 12 whereby it may be attached to the pipes Y and Z. F or the purpose of temporarily receiving the water of condensation which is precipitated in the main reservoir D, the casing 10 is provided with a receiving chamber or container 13. For the purpose of controlling the ingress and egress of the water, the container 13 in turn communicates with a plurality of cylindrical piston chambers 14 and 15 preferably located in alinement, one above and one below-the c0ntainer, such chambers being adapted to receive a duplex piston valve device 16 comprising a rod 17 connecting piston-heads 18 and 19 disposed respectively within the cylinders 14 and 15. The piston chamber 14 is provided at its lower portion (below the piston head 18) with a passage 20 whereby communication in the present case with the pipe Y, may be established, and said piston chamber 14: is provided at its upper portion (above the piston head 18) with a passage 21 whereby communication in the present case with the pipe Z, is established. The opening in the upper portion of the chamber 14 provided for the introduction of the piston head 19 with one or more discharge ports 24: communicating with the atmos-' phere. To normally close the bottom of the chamber 15a threaded plug 25 is provided. such plug being recessed as indicated at 26 for the reception of coiled spring 27, one

.end of which is adapted to bear against the piston head 19 and thereby normally support the duplex piston device 16 in the position shown in the drawings.

tat ails For manually establishing communication between the container 13 and the ports 24; and thereby discharging the contents of the container 13 to the atmosphere, I provide a pull-down rod 28 passing through the plug 25 and the spring 27 and afixed to the under surface of the piston head 19.

The pistons 18 and 19 are of substantially the same diameter so that the pressure of the air admitted through the passage 20 from the main air reservoir D on the two pistons counter balance with the result that the duplex piston valve device is operated by the difference in pressure above the piston l8 and the pressure below the piston 19.

-The pressure below the piston 19 is atmospheric owing to the provision of the passage 24 so that the force exerted on the duplex piston device is proportional to the extent to which the pressure above the pis ton 18 is greater than atmospheric. The spring 27 acts counter to this force and also to the force of gravity due to the weight or the duplex piston device and the spring is of such stren th that the pistons are normally held raisedin the position shown in Fig. 2. The spring can be made of such strength that the device will not operate until the pressure above the piston 18 reaches any predetermined value.

In the operation of the system above Jl'uferred to, with the drain-valve X in the position shown in Fig. 2 of the drawing, it will be observed that air entering the compressor A through the inlet B and thence forced through pipe G into the main reservoir D is normally restrained from egress therefrom through the pipe E by means of the engineers brake-valve F. It is further stopped from egrees through the ports 24. of the drain-valve X to the atmosphere by means of the piston head 19, the piston head 18 also serving to stop the passage of the air into the pipe Z. Since, however, the drain-valve X is below the main reservoir D. any water of condensation precipitated in the main reservoir D tends to drain through the pipe Y into the receiver or container 13 in the valve X. When, however, in the application of the brakes, the engineer opens the brake-valve F, (thus reducing the air pressure in the brake pipe H which vents to the atmosphere through the exhaust port K) thereby causing the triple valve R to operate and admit airfrom the auxiliary reservoir S through the pipe T into the brake cylinder V, as occurs in the operation of applying of the brakes, the pressure of the air in the pipe Z will rise. This rise in the pressure of the air entering the drain-valve device X through the passage 21ont0 the top of the piston 18, will overcomethe upward pressure of the spring 27 and force the piston valve device 16 downward, thereby closing the passage 20 and so interrupting the communication with the main reservoir D by means of the head 18, but causing the head 19 to completely traverse the ports 24: in such a manner as to place the chamber 13 into communication with said ports 24and thereby drain off the fluid contents of the chamber 13 and discharge the same to the atmosphere.

When, however, the brakes are released and the pressure in the members V, T, and Z simultaneously reduced to atmospheric, the spring 27 willlift the piston valve device 16 into the position shown in Fig. 2 of the drawing, thereby again interrupting the communication between the chamber 13 and the exhaust ports 24, and at the same time uncovering the passage 20, thereby restoring communication between the chamber 13 and the main reservoir D through the pipe Y. The drainage of the main reservoir is again initiated and maintained until the above described operation is repeated.

From the-foregoing description of my invention and of the method of its operation in the draining of the main reservoir of the air-brake system, it will be apparent that broadly considered, one of the essential features is the provision of a suitable means for controlling a pair of ports adapted for opening and closing in alternation so that there may be the minimized amount of direct con nection between any part of the air line and the atmosphere at the time the water of condensation is dischargedthis, in order, of course, to save the loss that would be ensuant upon dissipation of air pressure should the amount of direct connection be material; further, that while I have for purposes of convenience illustrated the application of my present improvements to a method of draining the main air reservoir by means of the admission of pressure from the auxiliary reservoir into the brake cylinder, the present improvements are susceptible of ready adaptation for the draining of any,

other part of the air-brake system, or, in fact, other fluid pressure devices wherein the pressure 1s variable, one of theessential features of my invention in this respect;

being the utilization of difi'erences in or graduation of the fluid pressurefor the operationof the discharge-port controlling means.

Having 'thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is :v

1. In an air brake system, the combination with amain air reservoir, and a brake cylinder, of a drain valve having discharge means, said drain valve being normally in communication with said main air reservoir and closedto said discharge means, and being further provided with means operable by variation in the fluid pressure in the brake cylinder for interrupting said communication with said main reservoir and establishing communlcation with the discharge means.

2. In an air brake-system,'the combination w1th a mam air reservoir, and a brake cylinder, of a drain valve having a fluid receivin chamber, and adischarge means, said dram valve being normally in communication with said main air reservoir and closed to said discharge means, and being further provided with means operable by variation in the fluid pressure in the brake cylinder for interrupting said communicaand closed to said discharge means, and be ing further provided with means operable by rise in the fluid pressure in the brake .cylinder for interrupting said communication with said main reservoir andestablishing communication wit the discharge means.

4. The combination with an air brake system including a main reservoir, of means for draining same main reservoir comprising a drain valve having discharge means, the said drain valve being normally in communication with said main reservoir and closed to the discharge means, and being further provided with means operable by variation in the fluid pressure in some part of the air brake system for interrupting said communication with said main reservoir and establishing communication with the dis charge means.

5. The combination with an air brake sysmined point, and provided with means operable by a further variation in the fluid pressure in some part of the air brake system for interrupting said communication with said main reservoir and establishing communication with the discharge means.

6. The combination with an air brake system including a main air reservoir, of means for draining said main reservoir comprising a drain valve having discharge means, said drain valve being arranged to beplaced alternately in communication with said main reservoir and with the discharge means, and being further provided with means operable by avariation in the fluid pressure in some part of the air brake system for efitecting such alternate communication.

7. The combination with an air brake system including a main air reservoir, of means for draining said main reservoir comprising a drain valve having discharge means, the said drain valve being arranged to be placed alternately in communication with said main reservoir and. with the discharge means, and being provided with a connection to some other part of the air brake system, and with means operable by the difference in pressure between the main reservoir and such other part of the air brake system for alternately closing and opening said discharge means.

8. The combination with an air brake system including a main reservoir, of means for drainin said main reservoir comprising a casing aving areceiving chamber communicating with said main reservoir and with a discharge means, a valve device in said casing for alternately opening and closing said communications operable by a variation in the fluid pressure in some part oi" the air brake system for effecting such alternate opening and closing.

9. lhe combination with an air brake system including a main reservoir, of means for draining said main reservoir comprising a casing having a receiving chamber ccm municating with said main reservoir and with a discharge means, a communication to some otherpart of the air brake system, and a duplex valve device automatically operable by the difi'erence in pressure between said main reservoir and such other part of the air brake system for alternately opening and closing said several communications. 7

10. The combination of a fluid pressure container and means for draining said container comprising a drainage device having a discharge outlet, said drainage device being arranged to be placed alternately in communication with some part of said fluid pressure container and with the discharge outlet, and being, further providedl with means operable by variation in the fluid pressure in some other part of the container for efiecting such alternating communication.-s' q a, i 11'. The combination of a fluid pressure container and meansfor draining said container comprising a drainage device having a dischargebutletgand having means for communication with a plurality of parts of said fiuid 'container, said drainage device being arranged to be placed alternately in communication with some part of said fluid pressure containeif and with the discharge outlet, and; being further provided with means operable by variation in the fluid pressure in some part of the container for effecting such alternating communication. 12. In an apparatus of the character derecreate scribed, in combination, a drainage device comprising a casing, an admission port'and a discharge port, and controlling means arranged to open and close said several ports in alternation, said controlling means being operable by variation of the pressure di rected thereagainst independently of the pressure in said admission port.

13. In an apparatus of the character described, in combination, a drainage device comprising a casing having a receiving chamber, a discharge port communicating with said chamber, an admission port, and controlling means arranged to open and close said several ports in alternation, said controlling means being operable by vari ation of the pressure directed thereagainst independently of the pressure in said admission port.

14. In an apparatus of the character described, in combination, a drainage device comprising a casing, an admission port and a discharge port, and controlling means disposed in said casing and arranged to open and close said several ports in alternation, said controlling means being operable by variation of the pressure directed thereagainst independently of thepressure in said admission port. a

15. In an apparatus of the character described, in combination, a drainage device comprising a casing, an admission port and a discharge port, and controlling means arranged to open and close said several ports in alternation, said controlling means being normally held in predetermined position by yieldingly resistant means and operable by variation of the pressure directed thereagainst independently of the pressure in said admission. port. v

16. In an apparatusof the character de scribed, in combination, a drainage device comprising a casing having a receiving chamber, a discharge port communicating with said chamber, an admission port, and controlling means disposed in said casing and arranged to open and close said several ports in alternation, said controlling means being operable by variation of the pressure directed thereagainst independently of the pressure in said admission port.

17. In an apparatus of the character described, in combination, a drainage device comprising a casing having a receiving chamber, a discharge port communicating with said chamber, an admission port, and controlling means arranged to open and close said several ports in alternation, said controlling means being normally held in predetermined position by yieldingly resistant means and operable by the variation of the pressure directed thereagainst independently of the pressure in said admission port.

18. In an apparatus of the character described, in combination, a drainage device comprising a casing, an admission port and a discharge port, and controlling means disposed in said casing and arranged to open and close said several ports in alternation, said controlling means being normally held in position by yieldingly resistant means and operable by variation of the pressure directed thereagainst independently of the pressure in sa1d admission port.

19. In an apparatus of the character described, in combination, a drainage device comprising a casing having a receiving chamber, a discharge port communicating with said chamber, an admission port, and controlling means disposed in said casing and arranged to open and close said several ports in alternation, said controlling means being normally held in position by yieldingly resistant means and operable by variation of the pressure directed thereagainst independently of the pressure in said admission port.

20.- In an a paratus of the character described in com lnation, a drain valve device comprising a casing having a receiving chamber, a pair of piston chambers arranged respectively on opposite sides of said receiving chamber, a duplex piston valve device having heads arranged in said chambers, the said casing being provided with passages extending therethrough arranged one on one side of each of said heads, and a passage extending therethrough arranged on the other side of one of said heads, one of said heads being arranged between a pair of said pressureconnections.

21. In an apparatus of the character described in combination, a drain valve device comprising a casing having a receiving chamber, a pair of piston chambers arranged respectively on opposite sides of said receiving chamber, a duplex piston valve device having heads arranged in said chambers,

the said casing being provided with passages extending therethrough arranged one onone side of each of said heads, and a passage extending therethrough arranged on the other side of one of said heads, one ofsaid heads being arranged between a pair of said pressure connections, yieldin ly resistant means acting on one of said hea s arranged to hold'v said valve device in predetermined position.

22. In an apparatus of the character described in combination, a drain valve device comprising a casing having a receiving chamber, a pair of piston chambers arranged respectively on opposite sides of said receiving chamber, a'duplex piston valve device having heads arranged in said chambers, the said casing being provided with passages extending therethrough arranged one on one side of each of said heads, and a passage extending therethrough arranged on the other side of one of said heads, one of said heads be ng arranged between a pair of sa1d pres- 23. In an apparatus of the character described, in combination a drain valve device comprising acasing having a receiving chamber, a pair of piston chambers arranged on opposite sides of said receiving chamber, a duplex piston device having heads arranged in said chambers, a discharge port and an admission port adapted to be opened and closed in alternation by said piston device, a source of variable pressure connected to one of said piston chambers and discharge means in the other of said piston chambers.

24. In an apparatus of the character described, in combination a drain valve device comprising a casing having a receiving chamber, a pair of piston chambers arranged on opposite sides of said receiving chamber, a duplex piston device having heads arranged in said chambers, a discharge port and an admission port adapted to be opened and closed in alternation by said piston device, a source of variable pressure connected to one of said piston chambers and discharge means in the other of said piston chambers, and yielding resistant means operating on said piston device in the opposite direction to said variable pressure. f

25. In an apparatus of the character decomprising a casing having a receiving chamber, a discharge port communicating with said chamber, an admission port, and controlling means disposed in said casing and arranged to open and close said several ports in alternation, each of said ports being closed before the other is opened, said controlling means being operable by variation of the pressure directed thereaga'inst.

26. The combination with a system employing fluid pressure including a container arranged to contain fluid at greater than'atmospheric pressure, of: means for draining the container comprismg a casing having discharge means, a valve therein, said cas-- ing being arranged to be placed in com munication with said container and with'--,

the discharge means, and being further provided with means operable by variation in the fluid pressure in some part of the system in the normal operation thereof for automatically effecting movement of said' valve and thereby opening and closing said discharge means. k

27. In an apparatus of the character described, in combination, a main fluid pressure container arranged to contain fluid at greater thanatmospheric pressure, a second container supplied with flllld obtained from 10.0 scribed, in combination, a drainage'device said main container, a drain valve for draining one of said containers, a discharge port in said valve, and means operated by change of pressure in one of said containers for moving said valve.

' 28. In an apparatus of the character described, in combination, a main fluid pressure container arranged to contain fluid at greater than atmospheric pressure, a second container supplied With fluid obtained from said main container, a casing adapted to receive liquid from one of said containers, a discharge port in said casing, a valve for interrupting flow of said liquid through said discharge port, means operated by rise of pressure in one of said containers for moving said valve into liquid discharge position.

29. In'an apparatus of the character described, in combination, a main fluid pressure container arranged to contain fluid at greater than atmospheric. pressure, a second container supplied with fluid obtained from said maincontainer, a casing adapted to receive liquid from one of said containers, a discharge port in said casing, a valve for interrupting flow of said liquid through said discharge port, and a piston device for actuating said valve subjected to the pressure in both containers on opposite sides thereof,

30. In an apparatus of the character dcscribed, in combination, a main fluid pres sure container arranged to contain fluid at ara-11s greater than atmospheric pressure, a second container supplied with fluid obtained from said main container, a casing adapted to receive liquid from one of said containers, a discharge port in said casing, a valve for interrupting flow, of said liquid through said discharge port, and a piston device for actuating said valve subjected to-pressure from one container on one side and to atmospheric pressure on the other side.

, 31. In an apparatus of the character described, in combination, a main fluid pressure container arranged to contain fluid at greater than atmospheric pressure, a second container supplied with fluid obtained from said main container, a casing adapted to receive liquid from one of said containers, a discharge port in said casing, a valve for interrupting flow of said liquid through said discharge port, a piston device for actuating said valve subjected to pressure from one container on one side and to atmospheric pressure on the other side, and resilient means acting on said piston device in the opposite direction to the pressure from said container.

in testimony whereof I I have hereuntosigned my name in the presence ofthe two subscribing Witnesses.

THOMAS W7. DEMAREST. Witnesses:

PAUL CARPENTER, P, McQUEENZ 

